Medical procedures involving precision insertion and placement of a therapy delivery device into a patient through a body portal are used to treat a variety of medical conditions. For example, electrical deep brain stimulation (DBS) to relieve chronic pain, or for the treatment of movement disorders, may necessitate the implantation, via a burr hole formed in the skull, of an electrode or lead. Similarly, burr holes are typically formed to allow implantation of a therapy catheter, e.g., an intraparenchymal (IPA) or intracerebroventricular catheter, to treat various ailments.
Use of such devices to deliver therapy to the brain generally involves determining: a cranial entry point; a depth to the desired target tissue location; and a device trajectory. To then accurately place the therapy delivery device, surgeons typically use stereotactic apparatus/procedures.
Stereotactic apparatus of varying configurations are known. For example, a “center-of-arc” stereotactic apparatus includes an arc-shaped frame wherein a center of the frame, as well as a pivot about which the frame is movable, aligns with the target tissue location. As a result, multiple device trajectory and entry points are available to reach the target location. Other stereotactic systems may utilize what is referred to as “frameless” or “microframe” technology. These systems typically utilize a pre-aligned, stereotactic platform custom-made for a particular patient's cranial physiology. Such systems may allow pre-operative alignment and configuration (potentially reducing the patient's time in the operating room) and may further result in less discomfort to the patient. These systems are advantageous in that they may also easily accommodate bilateral implantations.
While providing accurate device placement, microframe systems may present drawbacks. For example, the custom-made platform presents a recurring fee for each patient as compared to re-usable platforms. Moreover, it may take days to receive the custom platform after an order is placed, reducing the opportunity to offer same-day planning and surgery. Still further, such custom-made systems may have little or no ability to accommodate subsequent targeting adjustments when needed (e.g., when a large blood vessel is later found within the planned implant trajectory).